Error when trying to send message with attachment

Question

Hi,

I am trying to send a message using the C# graph api client using the following code...

 var draft = await client.Me.Messages                
                    .Request()
                    .AddAsync(message);

                await client.Me.Messages[draft.Id]
                    .Send()
                    .Request()
                    .PostAsync();  

Attachments are added is this way, where file is a
file in memory.

message.Attachments.Add(new FileAttachment
                {
                    ContentBytes = file.Content,
                    ContentType = file.ContentType,
                    ContentId = file.Id.ToString(),
                    Name = file.Name,
                    IsInline = false
                });

But I keep getting this error when attachment is eg. a pdf file. It works fine for emails without attachments or with eg. .png files attached.

Status Code: BadRequest
Microsoft.Graph.ServiceException: Code: ErrorUnsupportedTypeForConversion
Message: Unsupported type for restriction conversion.

Any help would be appreciated :)

Answer 1

I cant see what the content type and file name are in your case but I am able to add a pdf with the code below. Check this against what values you have and you should figure out what is wrong. I suspect file content, name or content type of the file in memory. Try with a file that you read like below (SDK version Microsoft.Graph/3.27.0)

byte[] contentBytes = System.IO.File.ReadAllBytes(@"sample.pdf");
string contentType = "application/pdf";
MessageAttachmentsCollectionPage attachments = new MessageAttachmentsCollectionPage();
attachments.Add(new FileAttachment
{
    ODataType = "#microsoft.graph.fileAttachment",
    ContentBytes = contentBytes,
    ContentType = contentType,
    ContentId = "sample-pdf",
    Name = "sample-1.pdf"
});
Message email = new Message
{
    Body = new ItemBody
    {
        ContentType = BodyType.Html,
        Content = "They were awesome!"
    },
    Subject = "Old guard talks at Noon",
    ToRecipients = new List<Recipient>()
    {
        new Recipient
        {
            EmailAddress = new EmailAddress
            {
                Address = "name@domin.onmicrosoft.com"
            }
        }
    },
    Attachments = attachments
};

// Create the message.
var draft = await graphServiceClient.Me.Messages.Request().AddAsync(email);
// Send the message.
await graphServiceClient.Me.Messages[draft.Id]
            .Send()
            .Request()
            .PostAsync();